Radio frequency (RF) front-end modules are utilized in mobile communication devices (e.g., laptops, cellular phones, tablets, etc.) to handle RF signals transmitted to the mobile communication devices and/or received by the mobile communication devices. Manufacturers and consumers of mobile communication devices continue to demand increasingly greater rates of data exchange (data rates) and the ability to handle RF signals formatted in accordance with an increasing variety of RF communication standards and RF communication specifications. As such, the RF front-end module may include RF transceiver circuitry with a plurality of different transmit chains and receiver chains in order to process the various types of RF signals. The RF front-end modules may thus include RF front-end circuitry, such as antenna switching circuitry, that allows for RF signals to be routed to the various transmit chains and receiver chains from one or more common antennas.
One way to achieve a high data rate in a mobile communication device is through the use of Multiple-Input and Multiple-Output (MIMO) techniques. For example, multiple RF receive signals may be received by an RF front-end module capable of implementing receive MIMO techniques. However, MIMO techniques present significant routing challenges to RF front-end modules. Current RF front-end circuitry often is not capable of implementing receive MIMO techniques without also causing significant isolation degradation between the various chains of the RF transceiver circuitry. Thus, RF front-end circuitry is needed that is capable of implementing receive MIMO techniques while maintaining adequate isolation.